This invention relates to an improved drying chamber. While the invention is described with particular reference to its application in x-ray film processors, those skilled in the art will recognize the wider applicability and inventive principals disclosed hereinafter.
X-ray film processors have generally become smaller and more compact than units previously available. These processors all require a plurality of processing stations for processing the film. Film processors of this type are often employed in dentist offices, in order to process x-ray pictures often made of the area to be treated prior to the actual treatment of a patient. A variety of such processors have been developed in the past. These include those described in U.S. Pat. Nos. 4,316,663, 4,086,607 and 5,040,012. In general, these processors includes a first tank containing a developing solution, a second tank for containing a fixer solution, and often include a third tank containing a cleaning solution, generally water, followed by a drying station for drying the processed films, as well as a film transport system for transporting the film through the processing stations and the developed drying station from a film loading point to a film discharge point.
The present invention is particularly concerned with the drying system of the processors. Three methods have been developed through which heat is transferred from one body to another. These include conduction, convection and infrared (IR) radiation. While x-ray film processes in the past have used radiation, infrared radiation per se has not permitted any increase in processor speed.
I have found that efficient infrared drying can occur by paying close attention to the frequency at which the infrared radiation is provided. For example, in the film processor described hereinafter, I have found that the infrared radiation should occur at a frequency that causes the water particles associated with the cleansing operation of the film processor, to resonate. By operating at the infrared heater at a frequency tuned to the material for which evaporation occurs, the water particles, for example, evaporate at higher rates, permitting faster operating times and reduced equipment size.
In addition, I have found that implementation of reflective coatings on the quartz tube that generates the infrared frequency, so as to reflect a higher number of the rays in the direction towards the film, also increases the heat transfer and evaporative capabilities of the processor. Preferably, a reflective coating on the quartz or heater tube that generates the infrared frequency over approximately one-half of the tubes external surface, in combination with the choosing of the tube operating frequency to correspond to the fluid for which evaporation is desired, enables one to increase significantly the speeds of the processor and reduce the film processing time to approximately sixty seconds per film.